I came across this when I found several solutions that didn't work for me. They all had there very own problems, they either had a debug option in it (which I found guilty of not starting my job after several hours of debugging) or other unnecessary keys.
To make this plist work, you should may create the corresponding log files before and give them the necessary permissions (770 worked for me, though it's maybe too much).
- Create the plist under ~/Library/LaunchAgents/com.user.boot2docker.plist
- run launchctl load ~/Library/LaunchAgents/com.user.boot2docker.plist